OP0133 THE DECREASE OF MUSCLE MASS BY THE BEHAVIORAL RESTRICTION OF COVID-19 PANDEMIC IN PATIENTS WITH RHEUMATOID ARTHRITIS
Authors: M. Tada, Y. Yamada, K. Mandai, Y. Matsumoto, N. Hidaka
Journal: Annals of the Rheumatic Diseases (2022)

Background We previously reported the prevalence of sarcopenia and body compositions at patients with rheumatoid arthritis (RA) 1 . The behavioral restriction of COVID-19 pandemic influenced for the lifestyle of people included patients with RA. Objectives The change of exercise and daily life activity of patients with RA were investigated and body composition and muscle function were compared pre- and post-behavioral restriction. Methods We used the date from prospective observational study (CHIKARA study: UMIN000023744). 70 from 100 patients with RA were followed-up and evaluated the change of exercise and daily life activity by visual analog scale. They were measured the muscle mass, fat mass, basal metabolic rate by body composition analyzer and grip strength as muscle function. The relationship between the change of exercise and daily life activity and body composition was investigated by univariate analysis. Results Mean age was 69.7 years (women n=57, men n=13). The rate of decrease of exercise by &lt;25%, 26~50%, and 51%&lt; were 70%, 21%, and 9%, respectively (mean:20% decrease). Whereas, the rate of decrease of daily life activities by &lt;25%, 26~50%, and 51%&lt; were 37%, 27%, and 36%, respectively (mean:44% decrease). Muscle mass at post-behavioral restriction decrease significantly compared that at pre-behavioral restriction activities (34.0kg vs 34.7kg, P&lt;0.001). Fat mass at post-behavioral restriction increase significantly compared that at pre-behavioral restriction (16.2kg vs 15.5kg, P=0.014). Grip strength at post-behavioral restriction decrease significantly compared that at pre-behavioral restriction (16.2kg vs 17.2kg, P=0.026). The change of exercise was significantly positively correlated with the change of muscle mass and basal metabolic rate (R=0.273, P=0.021 and R=0.256, P=0.033, relatively) at Table 1. Whereas, the change of daily living activities was not significantly correlated with the change of muscle mass and muscle function. Table 1. Univariate analysis of the changes in daily living activities or exercise and those in body composition or muscle function Change of daily living activities Change of exercise R value P value R value P value Δ Weight (kg) -0.123 0.311 -0.131 0.279 Δ BMI (kg/m 2 ) -0.108 0.397 -0.113 0.345 Δ Muscle mass (kg) 0.140 0.311 0.273 0.021 Δ Fat mass (kg) -0.061 0.614 -0.075 0.539 Δ Fat percentage (%) -0.003 0.982 -0.018 0.884 Δ Basal metabolic rate (kcal) 0.201 0.095 0.256 0.033 Δ Grip strength (kg) 0.117 0.336 0.037 0.762 Δ Walk speed (m/s) 0.169 0.161 0.139 0.250 Δ, change from pre- to post-behavioral restriction; BMI, body mass index Analyzed by Spearman’s rank correlation coefficient Conclusion Muscle mass and grip strength decrease and fat mass increase in patients with RA by the behavioral restriction of COVID-19 pandemic. Muscle mass and basal metabolic rate decrease in patients without exercise habits. Maintenance of muscle mass might be important during the COVID-19 pandemic. References [1]Tada, M., Yamada, Y., Mandai, K. &amp; Hidaka, N. Matrix metalloprotease 3 is associated with sarcopenia in rheumatoid arthritis - results from the CHIKARA study. Int J Rheum Dis 21, 1962-1969, doi:10.1111/1756-185X.13335 (2018). Disclosure of Interests None declared